CN105229295A

CN105229295A - Fuel injector

Info

Publication number: CN105229295A
Application number: CN201480029000.2A
Authority: CN
Inventors: G·A·米克; L·潘奈萨; M·C·维克斯顿
Original assignee: Westport Power Inc; Delphi International Operations Luxembourg SARL
Current assignee: Delphi Technologies IP Ltd; Westport Power Inc
Priority date: 2013-05-21
Filing date: 2014-05-21
Publication date: 2016-01-06
Anticipated expiration: 2034-05-21
Also published as: EP2999875B1; EP2999875A1; JP2016519249A; JP6336045B2; GB201309118D0; EP2999875A4; US20160115924A1; CN105229295B; WO2014186891A1; US10294908B2

Abstract

The invention discloses a kind of fuel injector for internal-combustion engine, preferred dual fuel injector.Described fuel injector comprises: the first and second needles (80,100), and it is provided to the injection of control first and second fuel; First and second control chamber (88,10), and it associates with described first and second needles (80,100) respectively; First control valve (26), it comprises the first control valve component (48) and is arranged to change the pressure that described first controls the control fluid in chamber (88), to cause the opening and closing campaign of described first needle (80); And second control valve (28), it comprises the second control valve component (60) and is arranged to change the pressure that described second controls the control fluid 10 in chamber (110), to cause the opening and closing campaign of described second needle (100).Described first and second control valve components (48,60) are provided so that along public control valve axis linear motion.

Description

Fuel injector

Invention field

The present invention relates to and be suitable for the fuel injector that control two kinds of different fuels are transported to internal-combustion engine.Particularly, but not exclusively, the present invention relates to the fuel injector being suitable for gas jet fuel and liquid fuel.

Background of invention

Internal-combustion engine for heavy duty and commercial Application is fuel usually with diesel oil.But, use rock gas to have the meaning of increase as Alternative Diesel Fuel.Rock gas is relatively sufficient and relatively inexpensive, and mainly can provide the power with diesel oil similar level, produces lower particle and nitrogen oxide (NOx) discharge simultaneously.

Rock gas can be used for replacing diesel oil and thinks that compression-ignition engine provides fuel, and wherein fuel combustion occurs as air in cylinder-fuel mixture compression result.But, because rock gas has the autoignition temperature higher than diesel oil, so need to start burning with pilot injection before introducing rock gas to firing chamber.

In the rock gas-driving motor of a type, be known as high pressure and directly spray (HPDI) motor, rock gas and diesel oil are all directly injected in firing chamber.Due to spatial constraints in engine cylinder cap, it is desirable that each cylinder uses a fuel injector to spray two kinds of fuel.This requires that fuel injector is particularly suitable in sparger, keep two kinds of fuel separately, and in due course between each fuel of independent conveying.

A kind of this kind of " double fuel " sparger describes in No. WO00/15956th, International Patent Application Publication.In this example embodiment, the fuel injector with concentric double nozzle structure is provided.Inner valve needle and outer needle engage with each valve base in its lower end thus control fuel flow through respectively interior group export and outer group export.What outer needle controlled rock gas is ejected through outer group of outlet, and inner valve needle control diesel injection is exported by interior group.Outer needle be tubulose to hold inner valve needle, and interior group export outside needle tip formed.

Inner valve needle and outer needle are independently controlled by two solenoid electric valves, and it is configured the pressure of indoor control fluid (usual diesel fuel) of each control chamber controlled for inner valve needle and outer needle.Control the upper end that chamber receives each needle, the pressure therefore changing the indoor control fluid of each control chamber can change downward (closedown) power on corresponding needle.Gas or diesel fuel pressure act on each needle thrust face down thus has an effect upwards (opens) power in needle.When the pressure controlling to control in chamber fluid is relatively high, downward force is greater than upward force, and each needle remains in valve base, and when controlling hydrodynamic pressure and being relatively low, upward force overcomes downward force, and each needle is opened thus allowed fuel to be ejected through each group of outlet.

Each control chamber is connected to control flow check body source in relatively high force.Each control valve is operatively connected each control chamber to the low pressure drain for controlling fluid.In like fashion, the opening of each control valve causes the reduction of the indoor control hydrodynamic pressure of corresponding control chamber, causes opening of corresponding needle.

Sparger is arranged in engine cylinder cap bore hole.Injector body extends through bore hole, and therefore injector tip extend in each firing chamber.The maximum diameter of cylinder head bore hole, and the free space that therefore restricted diameter of injector body is limited in cylinder head.Electromagnetic actuators for actuator control valve is usually too large and can not be contained in the main body of sparger.But actuator and control valve usually with and row arrangement is arranged on the top of fuel injector, therefore they reach above cylinder head.

Therefore, such sparger has relatively huge top, and it occupies the space in cylinder head upper area.Amount of space above the cylinder head that reduction sparger occupies is desirable, to be fuel rail and other engine pack vacating space.The present invention be directed to that this background makes.

Brief summary of the invention

First aspect, the invention reside in the fuel injector for internal-combustion engine, it comprises the first needle and the second needle that are configured to control first fuel and the injection of the second fuel, associate with the second needle with the first needle respectively first controls chamber and second controls chamber, comprise the first control valve component and be arranged to the indoor control hydrodynamic pressure of change first control chamber to cause the first needle to open and close the first control valve of motion, comprise the second control valve component and be arranged to the indoor control hydrodynamic pressure of change second control chamber to cause the second needle to open and close the second control valve of motion.First control valve component and the second control valve component are used for along public control valve axis linear motion through arranging.

By arranging the first and second control valves so that the first control valve component and the second control valve component align along public control valve door-hinge, control valve more effectively can configure installation in space than the sparger that can spray two kinds of different fuels known in the past.

Preferably, the first fuel is gaseous fuel, and the second fuel is liquid fuel.Such as, the first fuel can be rock gas, and the second fuel can be diesel oil.Controlling fluid can be the first fuel or the second fuel.Preferably, controlling fluid is diesel oil.

In first control valve and the second control valve, at least one can be contained in the basic cylindrical body part of sparger.In one embodiment, the first control valve and the second control valve are all contained in injector body part.In use, the main body of sparger is preferably arranged to be assemblied in engine cylinder cap bore hole.In like fashion, one or two control valve can be contained in the injector part that is contained in cylinder head bore hole, reduces the space that above cylinder head, sparger requires.

Preferably, control valve component basic liquid pressure balanced.In like fashion, the power that Mobile control valve door component requires is relatively little, and therefore thus control valve by relatively little actuator operated, can reduce the size of control valve.

In one embodiment, the first needle comprises the bore hole for receiving the second needle, and the first needle and the second needle removable along public needle axle.Control valve door-hinge can be in parallel with needle axle offset.

Control valve can be that solenoid valve activates.Respectively, fuel injector can comprise control valve assembly, and this valve member comprises common core component, for activating the first electromagnetic valve coil of the first control valve and the second electromagnetic valve coil for activating the second control valve.By being provided in the common core component shared between two control valves, the space occupied by control valve can reduce further.

In one embodiment, first control valve component and the second control valve component is each can move between filling position and exhaust position, wherein in filling position, each control valve component is embedding be sitting on valve base with prevent each control chamber and for control fluid low pressure drain between connection, in exhaust position, each control valve component promotes from valve base to allow the connection between each control chamber and low pressure drain.

First valve member can move to its exhaust position from its filling position in a first direction, and the second valve member can move to its exhaust position from its filling position in a second direction that is opposite the first direction.

In one embodiment, the first control valve component has the diameter larger than the diameter of the second control valve component.Correspondingly, first control the volume ratio second of chamber to control the volume of chamber large.

First control valve can be arranged to manage the fluid flowing controlling chamber from control flow check body source to first, with convenient first control valve component when its filling position, be allowed to from control flow check body source to the fluid flowing that first controls chamber, and when the first control valve component is at its exhaust position, be prevented from from control flow check body source to the fluid flowing that first controls chamber.

Alternatively or extraly, second control valve can be arranged to manage the fluid flowing controlling chamber from control flow check body source to second, with convenient second control valve component when its filling position, be allowed to from control flow check body source to the fluid flowing that second controls chamber, and when the second control valve component is at its exhaust position, be prevented from from control flow check body source to the fluid flowing that second controls chamber.

Accompanying drawing is sketched

, the present invention is described with reference to the drawings below only by way of example, wherein same reference numbers is used for similar features, and wherein:

Fig. 1 is the side view according to fuel injector of the present invention;

Fig. 2 is the side view of fuel injector partial cross section in Fig. 1;

Fig. 3 is the sectional view of fuel injector component in Fig. 1;

Fig. 4 is the perspective view of fuel injector component in Fig. 1;

Fig. 5 is the schematic diagram according to another fuel injector of the present invention; And

Fig. 6 (a), 6 (b) and 6 (c) are the schematic diagram of the fuel injector component according to the present invention's three variants.

Embodiment

With reference to Fig. 1 and 2, be generally elongated according to fuel injector 10 of the present invention in form.Fuel injector 10 comprises the injector body 12 and nozzle body 14 that are known as nozzle holder.Injector body 12 and nozzle body 14 are kept together by locking nut 16 with end-to-end structure, and locking nut and sparger cover 17 are with thread engagement.

The tip region 18 of nozzle body 14 comprises outer group of outlet 20 and inner outlet 22.As explained in more detail below, first fuel is controlled by first or outer needle (not shown in Fig. 1 and 2) by the injection of outer group of outlet 20, and the second fuel is controlled by second or inner valve needle (not shown in Fig. 1 and 2) by the injection of inner outlet 22.

As being clearly shown that in Fig. 2, injector body 12 is normally columned.Injector body 12 comprises control valve assembly 24, and it in figures 3 and 4 more in detail and separately illustrate.

Control valve assembly 24 comprises the first control valve usually represented by 26, and usual the second control valve represented by 28.First and second control valves 26,28 are all Electromagnetically actuated, and share common electrical magnet valve core component 30.Core component 30 shape is suitable for the basic tubular columns 32 of formation first and the second basic tubular columns 34.First and second column pieces 32,34 extend from annular towards outward flange 36 in the opposite direction.First electromagnetic valve coil 38 extends around the first column piece 32, and the second electromagnetic valve coil 40 is arranged around the second column piece 34.

Core component 30 and first and second coil 38,40 are contained in basic tubulose central injector main body part 42.Central injector main body part 42 is closed by the substantially cylindric injector body parts 44 in top at its upper end, and is closed by bottom injector body parts 46 in its lower end.Bottom injector body parts 46 have frusto-conical upper area and cylindrical lower part region.

First control valve 26 comprises the control valve component 48 (hereinafter referred to as the first control valve component) be received in slidably in top shooter main body part 44 in bore hole 49.First control valve component 48 is attached to discoid armature 50, and this armature 50 is contained in the recess (52) of the lower surface of top shooter main body part 44.In like fashion, the first column piece 32 of the contiguous core component 30 of armature 50 is arranged.The band of column 54 is arranged around the first coil 38 periphery, so that the band of column 54 is used as the column jacket of the first control valve 26.

First control valve component 48 is biased in primary importance by the first bias spring 56, is known as filling position.First bias spring 56 at one end engages with control valve component 48, and supports at the web 58 of its other end by the core component 30 separated by the bore hole of the first and second column pieces 32,34.When the first coil 38 is energized, armature 50 moves to the first column piece 32, the first control valve component 48 is sinked the second place, is known as exhaust position.In the orientation of Fig. 3, the first control valve component 48 is moving towards core component 30 downwards in exhaust position handoff procedure from filling position.

Similarly, the second control valve 28 also comprises control valve component 60 (hereinafter referred to as the second control valve component), and it to be received in bottom injector body parts 46 in bore hole 62 slidably.Second control valve component 60 is attached to discoid armature 64, and this armature 64 is contained in the recess (66) of the upper surface of bottom injector body parts 46.Therefore the second column piece 34 lower end of the contiguous core component 30 of armature 64 is arranged.In this embodiment, the diameter of the armature 64 of the second control valve 28 is similar to the diameter of the second column piece 34, and does not provide column jacket in the second control valve 28.

Second control valve component 60 is biased in primary importance by the second bias spring 68, is known as filling position.Second bias spring 68 at one end engages with the second control valve component 60, and supports at the web 58 of its other end by core component 30.When the second coil 40 is energized, the armature 64 of the second control valve 28 moves to the second column piece 34, the second control valve component 60 is sinked the second place, is known as exhaust position.

In the orientation of Fig. 3, the second control valve component 60 is upwards moving towards core component 30 in exhaust position handoff procedure from filling position.Therefore, when each control valve 48,60 moves from respective filling position towards respective exhaust position, the second control valve component 60 moves towards the first control valve component 48 in the opposite direction.

First and second control valve components 48,60 are arranged along common shaft, are known as control valve door-hinge.As being clear that from Fig. 2, the Axial and radial of control valve door-hinge and nozzle body 14 offsets, and therefore inner valve needle and outer needle (shown in Fig. 2) can move along this axle.

First and second coils 38,40 are independently controlled by electronic control unit.The electrical connection of each coil 38,40 is realized by the internal connector 70 be contained in side by side in central injector main body part 42 with core component 30.Bore hole 72 extends through top shooter main body part 44 and central injector main body part 42, thus receives electrical cnnector (not shown).Bore hole 72 extends through the relative thick parts of central injector main body part 42 and top shooter main body part 44 wall, and this wall produces as control valve axle offset position result.

Fig. 5 is the diagram that the fluid between parts in accordance with another embodiment of the present invention in control valve assembly 24, nozzle body 14 and nozzle peripheral connect connects.For the sake of clarity, many features of control valve assembly 24 are omitted in Fig. 5; First and second control valve components 48,60 are only shown.The sparger of Fig. 5 is generally similar to the sparger described referring to figs. 1 to 4, and with reference to the description of feature above for no longer describing below explaining.

In this embodiment, the tip region 18 of nozzle body 14 comprises the circular orifice 18a that the outer needle 80 of tubulose stretches out through it.Outer needle 80 engages with embedding seat region 82 thus controls the first fuel by organizing the flowing exporting (not shown) outside downstream, embedding seat region 82.In the lower member of nozzle body 14, the annular accumulator volume 84 for the first fuel is arranged around outer needle 80.When the embedding seat region 82 of outer needle and its is engaged, the fuel from accumulator volume 84 can be stoped to flow through outer group of outlet, and when outer needle 80 promotes from its embedding seat region 82, fuel can be exported to be ejected into engine chamber from accumulator volume 84 by outer group.

First fuel is supplied to accumulator volume 84 by service duct 86 in the wall of nozzle body 14.When in using, sparger is arranged in cylinder head (not shown), service duct 86 aims at the tank circuit in cylinder head, and the first fuel is fed to sparger from this tank circuit.

The movement of outer needle 80 is by changing the pressure that controls fluid in the first control chamber 88 and hydraulic control.First controls chamber is arranged in the nozzle body 14 of outer needle 80 upper end.The upper surface of outer needle 80 controls hydrodynamic pressure in chamber 88 to first and exposes.

Control fluid and inject the first control chamber 88 by first fluid control inlet passage 90.First controls fluid inlet channel 90 comprises current limliting aperture or throttle valve 90a, and it is used for limiting and controls the flow velocity that fluid flows into the first control chamber 88.

Referring again to Fig. 4, by first, first controls chamber 88 safeguards that path 92 is connected to the first control valve 26, it comprises a series of interconnection boring, and described boring extends through nozzle body 14, lower nozzle main body part 46, intermediate noxzzle main body part 42 and upper nozzle main body part 44.Safeguard that the annular valve chamber 93 that path 92 and the upper end 98 around the first control valve 48 are arranged is connected.

Referring again to Fig. 5, control fluid supply path 94 and comprise further series interconnection boring, described boring extends through nozzle body 14, bottom injector body parts 46, central injector main body part 42 and top shooter main body part 44.Control fluid supply path 94 and be connected to the second control fluid inlet channel 96 in nozzle body 14.When sparger is installed, first and second control the control fluid of fluid inlet channel 90,96 reception from the relatively high pressure of the tank circuit in cylinder head bore hole (not shown).

Control the branch road 94a said supply of control fluid of fluid supply path 94 to the tank circuit associated with the first control valve component 48.First control valve component 48 comprises shoulder (not shown), and described shoulder can engage with the embedding seat region (not shown) of the first control valve bore hole 49, thus forms the first base of the first control valve component 48.The end 98 of the first control valve component 48 can be engaged with the embedding seat region limited on sparger cover 17 lower surface (another reference drawing 1 and Fig. 4), thus forms the second base of the first control valve component 48.The discharge passage (representing with 95 in Fig. 3) formed in sparger cover 17 is provided in the downstream of the second base.Discharge passage is connected to the low pressure drain for controlling fluid.

When the first control valve component 48 is at its filling position, shoulder is thrown off from its embedding seat region, allows control fluid to flow through the first base from the tank circuit and enters annular cavity 93, and safeguard that path 92 enters the first control chamber 88 by first.Meanwhile, the end 98 of the first control valve component 48 is engaged with its embedding seat region, therefore controls fluid and can not flow into emission path 95 from annular cavity 93 by the second base.In like fashion, the control fluid that chamber 88 is filled with relatively high force is controlled.Act on outer needle 80 make a concerted effort be not enough to keep outer needle 80 by embedding seat, thus stop first fluid spray from sparger.

Be energized when the first coil 38 thus move the first control valve component 48 to its exhaust position, shoulder engages with its embedding seat region, thus stops the inflow of control fluid to safeguard path 92 at first of the first base.Meanwhile, the end 98 of the first control valve component 48 is thrown off from its embedding seat region thus is allowed the control fluid safeguarded path 92 first to flow into low pressure drain.By throttle valve 90a, control fluid and control from first speed that chamber 88 flows out to floss hole and exceed and control fluid and control from first the speed that fluid inlet channel 90 flows into the first control chamber 88.In like fashion, the first pressure controlling to control in chamber 88 fluid reduces, and allows outer needle 80 to promote from its embedding seat, to cause the first fuel in accumulator volume 84 to be sprayed by outer group of outlet.

In order to stop the first fuel to spray, the first coil 38 is de-energized, and therefore its filling position retracted by the first control valve component 48.First pressure controlling to control in chamber 88 fluid increases again, forces outer needle 80 to enter its operating position.Returnning spring 99 to be contained in the first control chamber 88 thus to provide extra closing force for outer needle 80, and this keeps outer needle 80 by embedding seat when sparger does not operate.

Inner valve needle 100 is contained in the bore hole of the outer needle 80 of tubulose, and therefore inner valve needle 100 and outer needle 80 are arranged along public needle axle.Inner valve needle 100 can the tip of needle 80 outside engage with embedding seat region 80a, thus controls the inner aperture of the second fuel through outer needle 80 tip or the flowing of aperture group (not shown).

Annular accumulator volume 102 for the second fuel is arranged between inner valve needle 100 and outer needle 80.When inner valve needle and its embedding seat region 80a engages, from accumulator volume 102 through aperture fuel flowing be prevented from, and when inner valve needle 100 promotes from its embedding seat region 80a, fuel can from accumulator volume 102 through the aperture for spraying by entering the firing chamber of motor.

Second fuel is supplied to accumulator volume 102 by service duct 104 in the wall of nozzle body 14, and described service duct is connected with the annular tank circuit 106 extended outside outer needle 80.Multiple radial bore 108 allows the second fuel flow through outer needle 80 from the annular tank circuit 106 and enter accumulator volume 102.When sparger is in use arranged in cylinder head (not shown), aim at for the tank circuit in the cylinder head that service duct 104 and second fuel of the second fuel is provided to wherein.

The annular tank circuit 106 is as fluid seal effect thus prevent from the first fuel leakage in accumulator volume 84 from controlling chamber 88 and second to first controlling in chamber 110.Therefore, in the tank circuit 106, the pressure of the second fuel can remain on the level higher than the first fuel pressure in accumulator volume 84.

The motion of inner valve needle 100 is by changing the pressure that controls fluid in the second control chamber 110 and hydraulic control.Second controls the upper end that chamber 110 is limited to outer needle 80 bore hole.The upper surface of inner valve needle 100 controls chamber 110 fluid pressure to second and exposes, and the second control chamber 110 separates with the accumulator volume 102 being used for the second fuel by the piston area 112 of inner valve needle 100 magnifying diameter.

Control fluid and inject the second control chamber 110 by the 3rd fluid inlet channel 114.3rd controls fluid inlet channel 114 comprises current limliting aperture or throttle valve 114a, and it is for limiting flow velocity when controlling fluid inflow second control chamber 110.When having installed sparger, the 3rd controls fluid inlet channel 114 tank circuit from cylinder head bore hole (not shown) has received the control fluid of relatively high force.

Second control chamber 110 safeguards that path 116 is connected to the second control valve 28 by second, its by extend through nozzle body 14 and enter bottom injector body 46 boring formed.There is provided multiple radial bore 117 in outer needle 80 thus allow the second control chamber 110 and the 3rd to control fluid inlet channel 114 and second and safeguard that the fluid between path 116 is communicated with.Control the branch road 94b said supply of control fluid of fluid supply path 94 to the tank circuit 94c associated with the second control valve component 60.

Second control valve component 60 comprises shoulder (not shown), and described shoulder can engage with the embedding seat region (not shown) of the second control valve bore hole 62 thus form the first base of the second control valve component 60.The end 118 of the second control valve component 60 can be engaged with the embedding seat region limited on nozzle body 14 upper surface thus form the second base of the second control valve component 60.The discharge passage 120 formed in nozzle body 14 is provided in the downstream of the second base.Discharge passage 120 is connected to the low pressure drain for controlling fluid.

The class of operation of the second needle 100 is similar to the operation of the first needle 80.When the second control valve component 60 is in its filling position, shoulder is thrown off from its embedding seat region, allows control fluid to flow through the first base from tank circuit 94c and safeguards that path 116 arrives the second control chamber 110 by second.Meanwhile, the end 118 of the second control valve component 60 is engaged with its embedding seat region, therefore controls fluid and can not flow into discharge passage 120 by the second base.In like fashion, the second control chamber 110 fills the control fluid with relatively high force.The enough maintenance inner valve needles 100 of making a concerted effort acting on inner valve needle 100, by embedding seat, thus stop the second fuel to spray from sparger.

When the energized thus mobile second control valve component 60 of the second coil 40 is to its exhaust position, shoulder engages with its embedding seat region thus stops controlling fluid and flows into from tank circuit 84c and safeguard path 116 at second of the first base.Meanwhile, the end 118 of the second control valve component 60 is thrown off from its embedding seat region thus is allowed second to safeguard path 116 that controlling fluid flows into low pressure drain by discharge passage 120.By throttle valve 114a, control fluid and control from second speed that chamber 110 flows out to floss hole and exceed and control fluid and control from the 3rd the speed that fluid inlet channel 114 flows into low voltage control chamber 110.In like fashion, the second pressure controlling to control in chamber 110 fluid reduces, and allows inner valve needle 100 to promote from its embedding seat 80a, to cause the second fuel in accumulator volume 102 to pass through small hole injection.

In order to stop the injection of the first fuel, the second coil 40 is de-energized, and therefore the second control valve component 60 is moved back into its filling position.Second pressure controlling to control in chamber 110 fluid promotes again, forces inner valve needle 100 to enter its closed position.Returnning spring 122 is contained in the second control chamber 110, thus provides extra closing forces to inner valve needle 100, and it is not when sparger exists, and keeps inner valve needle 100 by embedding seat.

In the embodiment shown, the diameter of the first control valve chamber 48 is larger than the diameter of the second control valve component 60.As a result, by each position first control valve 26 than higher by the flow rate of the control fluid of the second control valve 28 be possible.This reflection first controls the relative volume of chamber 88 and the second control chamber 110.

Should be appreciated that, in the embodiment shown in fig. 5, the first control valve component 48 and the second control valve component 60 are arranged along public Control Shaft, this public control valve door-hinge and the public needle axle offset along the offset direction orthogonal with the plane of figure.

By arranging the first and second control valves so that the first and second valve members are arranged along public control valve door-hinge, and by providing common core component for two valves, valve can the effective mode in space be contained in injector body.The use of common core component also promotes the use of inner integrated electrical cnnector.

Advantageously, the first and second control valves are " compensation flap " type.In other words, the first control valve component 48 and the second control valve component 60 are configured to owing to controlling the power acting on valve member that causes of fluid substantially by hydro-cushion.

For this reason, the first control valve component 48 comprises through bore hole 48a, as being clear that in Fig. 3.Through bore hole 48a is communicated with low pressure drain passage 95, and therefore low voltage control fluid injects the bore hole of the first column piece 32 and the second column piece 34.In like fashion, the two ends of the first control valve component 48 expose low voltage control fluid.The shape of the end 98 of the first control valve component 48 is suitable for being exposed to the frustroconical having area of contour in the plane orthogonal with control valve door-hinge, and this area of contour equals the area that the first control valve component 48 opposite end (lower end) presents in the same plane.Therefore equal pressure acts on the equal areas of the first control valve component 48, and does not produce clean hydraulic coupling when the first control valve component 48 is at its filling position.

Similarly, the two ends of the second control valve component 60 all expose low pressure drain fluid.In web 58, aperture (not shown) injects the bore hole of low voltage control fluid to the second column piece 34, thus acts on the upper end of the second control valve component 60.The lower end of the second control valve component 60 exposes the control fluid of same low pressure in discharge passage 120 (referring to Fig. 5), and the area of contour of often holding of the second control valve component 60 is all equal, therefore, when the second control valve component 60 is in its filling position, clean action of hydraulic force is not had in the second control valve component 60.

The important advantage using the valve member of hydro-cushion is that the power that operation control valve door requires is relatively low.And then it means that bias spring 56,68 can relatively low pressure and be compact, also mean that coil 38,40 can be relatively little, and the diameter of armature 50,64 can be relatively little.In like fashion, valve can be packaged in the diameter big envelope of injector body, and is therefore in use contained in cylinder head.This significantly reduces the amount of space that above cylinder head, in areas of congestion, sparger occupies, and reserves more spaces thus hold valve system and other engine component.In addition, in this configuration, the control chamber that control valve can associate with it is relative, and near installing, this minimizes the hydraulic pressure volume of control circuit, and therefore contributes to realizing good needle response and controlling.

Another advantage of the valve of hydro-cushion is that they are to the presser sensor controlling fluid.This means that they can keep operating in the flow rate of wide range and operation pressure, and the control valve assembly of same design can be used for multiple application.

In the embodiment shown in fig. 5, the first control valve 26 and the second control valve 28 are " three-dimensional " valves.Therefore, each control valve 26,28 for connecting each control chamber 88,110 when exhaust position to low pressure drain, and connects each control chamber 88,110 to the high-voltage power supply controlling fluid when filling position.Control fluid and control fluid inlet channel 90,114 to the flowing controlling chamber to the flowing increase control fluid controlling chamber 88,110 through first and the 3rd, cause needle quick closedown.

In variant of the present invention, one of the first control valve 26 and the second control valve 28 or both can be configured to " two-way " valve.In two way valve, valve only for connecting each control chamber 88,110 to low pressure drain, and does not provide the connection to high pressure control fluid source.But recharging of each control chamber 88,110 controls fluid inlet channel 90,114 generation by means of only first or the 3rd.

Fig. 6 schematically shows the control valve assembly that may change for the present invention three kinds.Fig. 6 (a) illustrates the control valve assembly of embodiment in Fig. 5, and wherein the first control valve 26 and the second control valve 28 are three-way type.As explained above, in this configuration, need to provide the fluid service duct 94 controlling to be extended by whole control valve assembly 24.

Fig. 6 (b) illustrates control valve assembly 224, and wherein the first control valve 226 is two-way type, and the second control valve 228 is three-way type.In this variation, control fluid service duct 294 and only extend in sub-body housing 246, control fluid service duct here by branch road 294b said supply of control fluid to the second control valve component 260.Control fluid service duct 294 and do not extend into intermediate host housing 242 or upper body housing 244, thus reduce the step manufacturing sparger and comprise, and be that in injector body, other components produce more spaces.Therefore, when maintenance second fuel spray optimal control be favourable time, but when weakening first fuel injection duration control thus reduce manufacture cost or formed space saving can accept time, the variant of Fig. 6 (b) is useful.

Fig. 6 (c) illustrates control valve assembly 324, and wherein the first control valve 326 and the second control valve 328 are two-way type.In this configuration, do not need to control fluid service duct.Therefore, compared with the variant of Fig. 6 (c), the manufacture of the variant of Fig. 6 (a) significantly more simply and more cheap, and provides more spaces in bottom injector body component 346, central injector component 342 and top shooter main component 344.

The control valve used in the above embodiment of the present invention can be any suitable type.The example with the control valve assembly being applicable to common core component of the present invention can find in the European patent EP 0987431 of such as the applicant and EP1670005.The example being applicable to the three-way pilot valve door of balance of the present invention can find in the European patent EP 1541860 of such as the applicant, EP1604104, EP1988276 and EP2290219.The example being applicable to balance double-direction control valve of the present invention can find in the European patent EP 0740068 of the applicant, EP0957262 and EP1835171.

In an example shown, the first control valve has relatively large diameter armature and column jacket, and the second control valve have relative minor diameter armature and without column jacket.Be appreciated that the first control valve can have the armature of relative minor diameter on the contrary and without column jacket, and/or the second control valve can have relatively large diameter armature and column jacket.

It is contemplated that, the first and second control valves can have core component separately.First and second control valves can along fuel injector length axially-spaced.Such as, replace in invention (not shown) one, the first control valve is arranged on the upper end of sparger, and away from nozzle body, and the second control valve is arranged in the injector body of nozzle body.In this configuration, when sparger is installed within the engine, it is outside that the first control piece is contained in cylinder head bore hole.

Control valve door-hinge does not need to depart from valve needle.But control valve door-hinge and needle axle can be concentric.

When the first fuel is vaporized fuel, as rock gas, and the second fuel is liquid fuel, during as diesel oil, can find that the present invention is particularly useful.First or second fuel also can be used as controlling fluid.In a particularly advantageous embodiment, the second fuel is diesel oil and is used as to control fuel.

Also the further modifications and variations clearly do not described above can considering, and the protection scope of the present invention not departing from claim restriction of enclosing.

Claims

1. the fuel injector for internal-combustion engine (10), it comprises:

First and second needles (80,100), it is provided to the injection of control first and second fuel;

First and second control chamber (88,110), and it associates with described first and second needles (80,100) respectively;

First control valve (26), it comprises the first control valve component (48) and is arranged to change the pressure that described first controls the control fluid in chamber (88), to cause the opening and closing campaign of described first needle (80); And

Second control valve (28), it comprises the second control valve component (60) and is arranged to change the pressure that described second controls the control fluid in chamber (110), to cause the opening and closing campaign of described second needle (100);

Wherein said first and second control valve components (48,60) are provided so that along public control valve axis linear motion.

2. fuel injector according to claim 1, wherein said first fuel is gaseous fuel, and wherein said second fuel is liquid fuel.

3. fuel injector according to claim 2, wherein said control fluid is described second fuel.

4. the fuel injector according to aforementioned any one of claim, in wherein said first and second control valves (26,28), at least one is contained in the basic cylindrical body part (42,44,46) of described sparger (10).

5. fuel injector according to claim 4, wherein said first and second control valves (26,28) are all contained in the main body (42,44,46) of described sparger (10).

6., according to claim 4 or fuel injector according to claim 5, the main body (42,44,46) of wherein said sparger (10) is arranged in use be assemblied in described engine cylinder cap bore hole.

7. the fuel injector according to aforementioned any one of claim, wherein said control valve component (48,60) is substantially for hydro-cushion.

8. the fuel injector according to aforementioned any one of claim, wherein said first needle (80) comprises the bore hole for receiving described second needle (100), and wherein said first and second needles (80,100) can move along public needle axle.

9. fuel injector according to claim 8, wherein said control valve door-hinge and described needle axle depart from and in parallel.

10. the fuel injector according to aforementioned any one of claim, it comprises control valve assembly (24), and described control valve assembly (24) comprises common core component (30), for activating first electromagnetic valve coil (38) of described first control valve (26) and the second electromagnetic valve coil (40) for activating described second control valve (28).

11. fuel injectors according to aforementioned any one of claim, wherein said first control valve component (48) and described second control valve component (60) is each can move between filling position and exhaust position, wherein in filling position, each control valve component (48, 60) to be embeddingly sitting on valve base to prevent described each control chamber (88, 110) and for described control fluid low pressure drain between connection, in exhaust position, each control valve component (48, 60) promote from described valve base to allow described each control chamber (88, 110) connection and between described low pressure drain.

12. fuel injectors according to claim 11, wherein said first valve member (48) can move to its exhaust position from its filling position in a first direction, and wherein said second valve member (60) can move to its exhaust position from its filling position in second direction opposite to the first direction.

13. according to claim 11 or fuel injector according to claim 12, and the diameter of wherein said first control valve component (48) is larger than the diameter of described second control valve component (60).

14. fuel injectors according to any one of claim 11 to 13, wherein said first control valve (26) is arranged to manage the fluid flowing controlling chamber (88) from control flow check body source to described first, with the described first control valve component (48) of box lunch when its filling position, be allowed to from described control flow check body source to the fluid flowing that described first controls chamber (88), and when described first control valve component (48) is at its exhaust position, be prevented from from described control flow check body source to the fluid flowing that described first controls chamber (88).

15. fuel injectors according to any one of claim 11 to 14, wherein said second control valve (28) is arranged to manage the fluid flowing controlling chamber (110) from described control flow check body source to described second, with the described second control valve component (60) of box lunch when its filling position, be allowed to from described control flow check body source to the fluid flowing that described second controls chamber (110), and when described second control valve component (60) is at its exhaust position, be prevented from from described control flow check body source to the fluid flowing that described second controls chamber (110).